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I'm certainly not going to work on the 500th floor
August 26, 2012 9:34 PM   Subscribe

How tall can buildings get, anyway?
posted by Chrysostom (94 comments total) 19 users marked this as a favorite

 
Please note space elevators are explicitly excluded.
posted by Chrysostom at 9:34 PM on August 26, 2012 [4 favorites]


Short answer: as tall as a space elevator.
Long answer: Available resources are the only limit.
posted by IAmBroom at 9:38 PM on August 26, 2012 [2 favorites]


Well, there is that old calculation about high you could have a building before the pressure from all the stuff above exceeds the bond strength of the atoms at the bottom. The idea is that adding more atom on top would basically squeeze out an atom at the bottom and you'd be left with the same height. The number you get is several Everests....IIRC, which is not terrible a spherical cow type set of assumptions.

Now of course none of that takes into account some "active" structures like a space fountain or something.
posted by Chekhovian at 9:38 PM on August 26, 2012 [1 favorite]


I remember hearing a thing on the radio (can't remember which show) which talked about how mountains on Earth have a limit they can reach which has to do with gravity and such. And that's why there are mountains on other planets, like Mars, which are a lot taller. It's not because that planet is simply lucky, but that its lower gravity allows for mountains to get taller.

I don't doubt this is the same for buildings. Eventually we could build a building as tall as Everest, but it would require the same kind of base footprint for support, etc.
posted by hippybear at 9:40 PM on August 26, 2012


its lower gravity allows for mountains to get taller

The pressure at the base is of course rho g h. Unless your building is REALLY TALL, then it would be some integral over newtons law of gravity haha. And I mean really tall, because "g" isn't even all that much lower at LEO.
posted by Chekhovian at 9:45 PM on August 26, 2012 [2 favorites]


Probably from the same radio show, I remember the architect pointing out that when you want to add one more story to skyscraper, you need to think of it as adding one at the bottom, not at the top.
posted by benito.strauss at 9:50 PM on August 26, 2012 [2 favorites]


How long does it take to get to the top of a kilometer-high building, anyway?
posted by leahwrenn at 9:53 PM on August 26, 2012 [1 favorite]


Depends on how fast you can climb stairs, I suppose.
posted by kavasa at 9:57 PM on August 26, 2012 [3 favorites]


How tall can buildings get, anyway?

357,000 km. After that you have to worry about the Moon hitting it.
posted by mazola at 10:04 PM on August 26, 2012 [1 favorite]


357,000 km. After that you have to worry about the Moon hitting it.

Can't you just point it the other way?
posted by Hicksu at 10:06 PM on August 26, 2012 [16 favorites]


Well, there is that old calculation about high you could have a building before the pressure from all the stuff above exceeds the bond strength of the atoms at the bottom

Tall buildings, like space elevators, could be logarithmically tapered so that they have a constant weight-per-supporting-area ratio. I assume that's what all the architects' references to the Eiffel Tower and X-Seed are referring to.
posted by hattifattener at 10:06 PM on August 26, 2012


That is what I am wondering, the new 1WTC will only be .3 miles high. The elevators are supposedly capable of going 2000 ft a minute.I am guessing like the old WTC they will have a system of express elevators and "sky lobbies" and maybe those new fangled control systems that are popping up in NYC that try to group passengers together to minimize stops.

The highest I ever worked, the 40th floor, it was longer waiting for an express elevator making stops on floors above mine than the trip between the ground and the first express stop on the 36th floor. This was a newer but kinda ghetto building in midtown.
posted by Ad hominem at 10:08 PM on August 26, 2012


The article does not discuss how above 8,000 feet MSL or so, it would probably be necessary to pressurize the floors of the structure. This likely adds considerable weight and could require smaller, airliner-like windows.
posted by Chef Flamboyardee at 10:22 PM on August 26, 2012 [7 favorites]


As an alternative, you could require penthouse occupants to wear cannulas and wheel around oxygen tanks.
posted by Chef Flamboyardee at 10:24 PM on August 26, 2012 [3 favorites]


On the 40th flood my ears hurt until about noon. I was always tempted to go into the stairwells, which were pressurized, but figured I would never get away with it. These days people take shit seriously, we evacuate when someone burns popcorn in the microwave or Air Force 1 comes too close.
posted by Ad hominem at 10:27 PM on August 26, 2012 [1 favorite]


So in the hollow base examples, what do you do with the hollow part? Is it empty or do you build a couple regular-sized buildings in there?
posted by RobotHero at 10:30 PM on August 26, 2012


Can't you just point it the other way?

Or build it at the South Pole.

The big problem with elevators (imo) is that human beings have to ride in them. You could probably make express elevators that zoomed up down the length of a building like race cars, but they would smoosh the people inside. So you're limited to fairly low acceleration and deceleration, and that puts a limit on how tall buildings can be if people need to travel their full height every day.
posted by Kevin Street at 10:38 PM on August 26, 2012


The big problem with elevators (imo) is that human beings have to ride in them. You could probably make express elevators that zoomed up down the length of a building like race cars, but they would smoosh the people inside. So you're limited to fairly low acceleration and deceleration, and that puts a limit on how tall buildings can be if people need to travel their full height every day.

Surely this is something someone smarter than me could express mathematically?

What's the theoretical maximum speed an elevator could reach, for, say, a two mile tall building? Assume it's going from the ground floor straight to the top. Clearly, the typical human's ability to absorb g-forces vertically have been well explored and documented, so if the energy and mechanics weren't an issue, what are the limits from a purely physiological perspective for humans?

And how much would the speed be increased (or the deceleration distance be reduced) if the occupants were lying on their backs? It seems you could launch faster, considering that's how we get to space, and because the force is dispersed along the entire body instead of into two feet, but slowing down's going to be a pain no matter what.

Really curious if the math's been done for these sort of theoretical maximums...
posted by disillusioned at 10:46 PM on August 26, 2012


The video from the article is very revealing; when you interview several experts in a field and they all have different opinions of what the hardest element would be, that either means that they don't know what they are talking about (not likely in this case; these are smart but practical people) or that it's a really hard problem. Note that none of them said physics, or structural engineering, or oxygen or any of this exotic stuff. The two things that they mention most frequently are the elevators and the economics, which intersect.

The higher you build a building, the more the elevators become an issue, both speed and capacity. A supertall office tower, like the Wills (Sears) Tower in Chicago or the World Trade Centers can have 20,000 or more workers in it. We're talking about 1 mile tall buildings, which are four times that height. Imagine it's lunchtime, and only half the workers want to go out for lunch. You have to get 40,000 people down to ground level within, what, two minutes? Five minutes? And I'm not even hinting at fire.

It's obviously stupid to make someone on the 300th floor get on an elevator that could stop at every.single.floor. all the way down. So there are express elevators, but even so, you need skylobbies to transfer (and transferring between express and local elevators is a pain). And an elevator is basically a box being held up by a cable; the cable is holding both the box and itself up, and as the elevator shaft goes taller, the cable needs to hold more cable, so it needs to be stronger, so it needs to be heavier, so it needs to be stronger, repeat ad infinitum. So you have multiple elevators, and multiple transfers. One of the key features of a skyscraper is you can have a lot of people all working together; if it's a 20 minute commute to the legal department 40 stories above, this defeats the purpose.

As buildings get taller, you not only need more elevators, but more structure. This makes the core of the building thicker and thicker, and either reduces the amount of floorspace you get up top as well as requiring a bigger and bigger lower level. This cuts into the fundamental economics of high rise construction; it must be cheaper to build really tall (with the expense of high-performing structures, the reduced floorspace per level, the elevator madness) than just to build a bunch of buildings. This means that land prices need to be insanely expensive and the transportation system incredibly effective. (A single lane of road handles 2,000 vehicles per hour - if you have only road access, our hypothetical mile-high, 80K worker building needs 40 lanes of road to let everybody drive there within an hour. A packed subway line is on the order of 20,000 passengers, so you need four subway lines converging at our building.) So there are about ten places on the planet where it may make economic sense to build supertalls. (Most of the supertalls are not actually in these ten places.)

At some point, everybody would be happier if you built four towers, 1/4 the height, right next to each other.

Which is why the only people in the supertall game are doing it for their own aggrandizement; oil-rich despots in the Middle East (and in Moscow), Taiwan and China flipping each other the metaphorical 101-story bird, the 1776 foot tall Freedom Tower. It's less a case of "how high can we build" but more a case of "who has so much money and so little common sense"?
posted by Homeboy Trouble at 10:55 PM on August 26, 2012 [53 favorites]


This was a really cool idea for an article that unfortunately fizzled out and the editor decided to publish it anyway. The salient part of the article, the part that you keep reading and waiting for, is totally anticlimactic: "I'm afraid I'm going to have to chicken out on you and not give you a number," says "the ultimate expert." Sure, you knew it was going to boil down to just one guy's opinion and of course there would be some hypothetical panel of experts out there who'd disagree with him...but still, you wanted to hear that one guy's opinion. Nope.
posted by cribcage at 10:56 PM on August 26, 2012


Really curious if the math's been done for these sort of theoretical maximums...

Lol, you mean high school level physics?

Assuming you spend half the time accelerating at your max a, and half the time decelerating, your distance should be aT^2/4, where T is the total time, and a is your max acceleration, say 3g maybe. So for an hour you'd get...97,200,000 m...if I haven't fucked up back of the napkin calculation...which is probably likely, given that I made fun of the simplicity of the calculation...
posted by Chekhovian at 10:59 PM on August 26, 2012 [3 favorites]


Elevator operators don't get to give the passengers a physical, so ignore figures from military fighter pilots. I imagine theme parks have already figured out the sweet spot in the acceleration vs. passenger death curve.
posted by ryanrs at 11:01 PM on August 26, 2012 [3 favorites]


the acceleration vs. passenger death curve

That is a plot I would very much like to see.
posted by Chekhovian at 11:03 PM on August 26, 2012 [2 favorites]


Space elevators aren't allowed?

Fine, how about a rigid geostationary orbital ring supported by multiple legs?

Also there are now plenty of plain old terrestrial elevators in tall buildings that move faster than 50-60 MPH. Since the movement of an elevator is mainly linear the upper speed limit of an elevator is really determined by the smoothness of the acceleration and deceleration. They're also now using extremely light weight and high tensile strength steel "tapes" instead of cables in ultramodern elevators.

Elevators are also very energy efficient people movers since they use counterweights.

It's less about the individual elevator speed as it is about the wait for elevator service and having enough elevators.
posted by loquacious at 11:04 PM on August 26, 2012


how about a rigid geostationary orbital ring supported by multiple legs?

Also impractical because it isn't shaped like a penis.
posted by ryanrs at 11:07 PM on August 26, 2012 [9 favorites]


(actually might want to rephased that as a funding issue)
posted by ryanrs at 11:08 PM on August 26, 2012 [2 favorites]


Obviously the real future is mixed use superscrapers or megatowers where you don't have to go from ground floor to 101 and back five times a day. You live on 75th, work on 101, go to a food kiosk in the skyrotunda on 80.

We are already making inroads. If you live and work at the Tme Warner Center in Columbus Circle and choose to shop at the Whole Foods there or eat at Per Se,Masa, or Bouchon Bakery every meal you never have to leave.
posted by Ad hominem at 11:10 PM on August 26, 2012 [2 favorites]


Somewhere right now, Clive Palmer is dreaming of building the Tower of Babel.
posted by Effigy2000 at 11:12 PM on August 26, 2012 [1 favorite]


From this article on elevators

Elevator speed: 1,010 meters per minute

Building height: 509.2 meters (1,671 feet)

The world's tallest building (soon to be overtaken by the Burj Dubai), the Taipei 101 has two express elevators that together hold the all-time record for speed. Time to the 87th floor observation deck: 37 seconds.


509 metres in 37 seconds is only 825 metres per minute, so I'll presume that 1,010 is the maximum speed that elevator reaches. And now the Burj Dubai is complete, maybe it's got something faster.

The logistics of how quickly you can load people in and out of the elevators and how much space in your building is taken up by shafts might be limiting factors more than acceleration.

I mean, there are plenty of people who commute more than 2 miles to go to work. But imagine if they were all taking the same stretch of road at the same time, and you had to divide that road into segments with dedicated buses that couldn't drive around each other, just drive forward and backward.
posted by RobotHero at 11:13 PM on August 26, 2012


Obviously the real future is mixed use superscrapers or megatowers where you don't have to go from ground floor to 101 and back five times a day.

But then don't all your archologies start launching into space?
posted by Chekhovian at 11:17 PM on August 26, 2012 [3 favorites]


But then don't all your archologies start launching into space ?

Let's not get crazy. We couldn't really build a mile high generational ship that could operate in megascraper mode until it was time to bug out could we? I bet the large hollow footprint would be a great place to put rockets.
posted by Ad hominem at 11:27 PM on August 26, 2012 [1 favorite]


We are already making inroads. If you live and work at the Tme Warner Center in Columbus Circle and choose to shop at the Whole Foods there or eat at Per Se,Masa, or Bouchon Bakery every meal you never have to leave.

Is there a weed dealer there? If so I probably wouldn't have to leave for a while.

Even so, and regardless how posh it might be, I would die a little inside every time I had to tell people I lived at the fucking Time Warner Center.
posted by krinklyfig at 11:33 PM on August 26, 2012 [1 favorite]


I thought the issue was that God would smite us and confound our tongues?
posted by iotic at 11:33 PM on August 26, 2012 [8 favorites]


Yeah, as Chef Flamboyardee is saying, I believe atmospheric pressure is the real limit. Per Wikipedia, the Boeing 767 pressurizes the passenger cabin to the equivalent of 6900 feet, 2100 meters, while the A380 pressurizes to 5000 feet, 1,500 meters.

They say that people with heart and lung disease can start seeing symptoms of hypoxia past 5000 feet. Considering that many of the world's richest people are also the world's oldest people, with the greatest likelihood of health impairment, I think 1,500 meters is the practical limit for building size, with maybe 2100 meters the limit for people willing to sign health waivers to go to work.

They could go higher if they could pressurize the building, but that would, I think, add a great deal of weight and expense. And I dunno about you, but majestic view or no majestic view, I'd be nervous about working in a building where I could just suddenly pass out, and eventually die, if the pressurization failed.
posted by Malor at 11:36 PM on August 26, 2012 [3 favorites]


i'd want seats in the elevators! and a nice book to read when I have to use them.
posted by cusack01 at 11:38 PM on August 26, 2012


Lying on your backs, ~3G is tolerated well enough that carnival rides subject people to that for extended periods of time. You'd need the car, or the bunks inside the car, to flip over for deceleration of course. Assuming a 2-mile building and an elevator subjecting its occupants to a constant 3 gravities (so, 2G acceleration upwards and 4G deceleration), you could get, ummmmmm, I have too much gin in me right now to do the actual math, but a 2-mile ride shouldn't take you much longer than 25-30 seconds.

I'm guessing most people over age 30 or so would elect to take the slower elevators whenever possible.

The obvious approach for super-tall buildings is to have most people spend most of their time inside the structure (arcologies, 'towers in the park', etc). The most difficult question then becomes political, because you have a small city all of whose real estate is (a) extremely expensive, (b) owned by one company, (c) interdependent in a way that a land-based city's never is. How do you govern that?

Engineering-wise I wonder how large a building could support traditional commuter-style traffic patterns though. I think you'd have to do away with elevators held by cables and move to a vertical-subway model in which multiple cars occupy the shaft at once, pulling into sidings to let people on and off, and so forth.
posted by hattifattener at 11:39 PM on August 26, 2012 [2 favorites]


"skypenetrator"

We have slipped the surly bonds of Earth to teabag the face of god, apparently.
posted by ShutterBun at 11:49 PM on August 26, 2012 [18 favorites]


skyscrapers are a grotesque and unconscionable display of waste and opulence, like everything that is not either poop or tempeh loaf or both
posted by This, of course, alludes to you at 12:13 AM on August 27, 2012 [2 favorites]


The "Willis Tower"? Illinois should have revoked the company's registration in that state as a matter of principle.
posted by crapmatic at 12:14 AM on August 27, 2012 [1 favorite]


I was able to tolerate my visit by pretending that the "Willis" in question was Wesley Willis

(Also I'm surprised some German simulator developer hasn't made a hobbyist elevator sim. For all I know they have commercial ones for architects, but I'm not well-connected in the vertical market's vertical market)
posted by jake at 12:33 AM on August 27, 2012 [5 favorites]


The "whatchoo talkin' about, Willis?" bill, so to speak?
posted by ShutterBun at 12:34 AM on August 27, 2012 [1 favorite]


I recently spent several days at a hotel at 2200 meters, par of that time above, and part below, that level. It wasn't a very big deal.

The very idea of people having to go down to street level, to get lunch, is absurd.

hattifattener for the Win! Outside the box! Elevators are sooooo last millennium. And maybe add some kind of external personnel delivery system. Why not? And when building mega-high, why can't towers be linked at higher-than-street level? (the film 5th Element used that, IIRC).

Personally, I'm ecstatic to read about the "Eiffel Tower" open base idea, since I pulled that out of my imagination decades ago. It seems obvious to me. But I also wanted the base to be a bridge over a river. :-)
posted by Goofyy at 12:36 AM on August 27, 2012


when building mega-high, why can't towers be linked at higher-than-street level?

Good idea
posted by ShutterBun at 12:40 AM on August 27, 2012


Is there a weed dealer there?

I though you could get weed delivered in New York City.
posted by ryanrs at 12:57 AM on August 27, 2012


Meanwhile in the other direction...
posted by tykky at 2:04 AM on August 27, 2012


Yes. Don't build up. Dig down.

For elevators, build comfortable enclosed seating pods that are automatically shunted vertically and horizontally from transportation hubs to building floors (if your ID card tells the pod that you can go there). There may be a pod traffic jam during rush hours. Just relax and check your mail while in transit. Eventually, your pod will be dumped on your floor and your pod door will pop open.

But also: don't ask people to go to the office every damned day of the week. You could work Mondays, Wednesdays, and Fridays at the main office, attend more than enough face-to-face meetings, and do the rest of your work from home or from generic branch offices nearer to living quarters. Get other businesses to buy into that pattern and you wouldn't have people scheduling meetings on days most people are at home. And, of course, let people telecommute. And... maybe live closer to work.
posted by pracowity at 2:05 AM on August 27, 2012


What is required for practical people transport is a super fast one-way non-stop express elevator from the lobby right to the top floor. Only two shafts are needed, one for up elevators and one for the returning empty cars going down. Multiple elevators can follow each other in the same shaft, like a vertical gondola cable cars. Since it is non-stop, modest acceleration will quickly reach the speed required to move the crowds of people arriving at work in the morning.

Once on the top floor, office workers can quickly descend to their offices via a series of hydro-slides and fireman's poles. Wheeeee...
posted by AndrewStephens at 2:06 AM on August 27, 2012


You know how every other day someone links to some photo series featuring the abandoned buildings of a once thriving Detroit?

Urban explorers and tedious photogs are going to jelly their jockeys when the oil economy goes belly up and the middle east is sprinkled with 2 mile high ghostscrapers.
posted by dgaicun at 2:23 AM on August 27, 2012 [9 favorites]


Yippie yi ohhhhh
Yippie yi yaaaaay
Ghost scrapers in the sky.
posted by pracowity at 2:29 AM on August 27, 2012 [2 favorites]


A single lane of road handles 2,000 vehicles per hour - if you have only road access, our hypothetical mile-high, 80K worker building needs 40 lanes of road to let everybody drive there within an hour. A packed subway line is on the order of 20,000 passengers, so you need four subway lines converging at our building.

Forget the 40 lanes of road-- it would need 25 million square feet of parking structures. But of course there's no sense in combining cars and towers.

But I think the busiest subway lines in the world are closer to 80,000 passengers per hour, so that part at least could be reasonably achieved.
posted by alexei at 2:44 AM on August 27, 2012


Metafilter: the sweet spot in the acceleration vs. passenger death curve
posted by zinon at 3:31 AM on August 27, 2012 [2 favorites]


"We are already making inroads. If you live and work at the Tme Warner Center in Columbus Circle and choose to shop at the Whole Foods there or eat at Per Se,Masa, or Bouchon Bakery every meal you never have to leave."

Except at some point you'd have to have a pretty wide spectrum of mixed-income housing and amenities. I'm picturing a scenario where at some point down the line gentrification is inevitable. All the janitors and maintenance workers end up living in the sub-baesements, meanwile the Supertower Times Style section writing smug articles about the hip clothing boutiques and artisinal pickle shops popping up on floors 35-60.
posted by billyfleetwood at 3:57 AM on August 27, 2012 [1 favorite]



Urban explorers and tedious photogs are going to jelly their jockeys when the oil economy goes belly up and the middle east is sprinkled with 2 mile high ghostscrapers.
This is basically the plot of Spec Ops: The Line.
posted by Elementary Penguin at 4:06 AM on August 27, 2012


Fundamentally, the limit on height of a *useful* office building or other occupied building (as opposed to towers like the Tokyo Skytree and CN Tower) is elevators.

You need elevators to get people up and down. As a building grows taller, you need more elevators. Elevators, however, take up space on every floor they pass through. At a certain point, you run out of room for them, unless you give up rentable space on each floor.

Speed is important too -- if you had every elevator stopping at every floor, you'd never get anywhere. So, you start getting complicated. Witness Sears Tower, with 104(!) elevators.

So, you get Sky Lobbies. There are a few dedicated elevators that move between the main lobby and the Sky lobbies on 33/34 and 66/67. Yes, two floors, and yes, they're double decked elevators -- you go up a set of escalators to reach the 2nd deck of the elevator.* There's also a pair that service the sky deck on 103 and the mechanical floors above them.

In the rest of the tubes run the local elevators, three per tube. The first connects the main lobby thru 32, the second connects the lower sky lobby thru 65, and the last connects the upper sky lobby to the rest of the upper floors. This way, instead of 1 elevator serving 110 floors, you have three elevators, each serving about 35 floors, in the same tube (thus, the same footprint) instead of three elevators serving all floors, in three separate tubes.

Skylobbies make our current tallest buildings work, but even they have limits. The Burj Khalifa, by far the tallest building in the world, has very little floorspace in the upper floors, and really, it appears that as we push over the 600m mark, making a rental building becomes basically impossible -- either it takes too long to get to the floor, the space on the floor is tiny, or both

The first building to use them is also in Chicago -- the John Hancock Center. The building itself is mixed commercial, with office space above, and then residential space above that. Residents enter the building on the north side, on Delaware Place, and take one of three elevators that stop at that lobby, at the parking garage entrance on the 6th floor, and the skylobby on 44. Two sets of elevators run from here, one running 45-65 and the other 65-92. Below them, elevators run from 1-43 for the commercial spaces. A set of four run from the lower and main lobbies to 92 and above, a pair of them for the Skydeck.

Also on that 44th floor Skylobby? A pool.


* The Sears Tower is an odd beast. Built to hold all of Sears' (then) mighty merchandising division, which included the fulfillment system behind the Sears Catalog, they needed a *lot* of space, and they wanted big, wide floors. However, they wanted room to expand, and they knew that smaller floors with better views would be easier to rent.

So, the architect, Bruce Graham, and the structural engineer, Fazlur Kahn, came up with a design that basically defined how super tall buildings would work. The tower is actually 9 75x75' towers built together. From floors 1-50, all nine climb, giving 225x255' floors. At 51, though, two of the tubes end -- on opposite corners -- leaving 7 to climb to 66. At 66, two more end, the other corners, leaving 5 in a cruciform patter to climb to 90. At 90, three more end, leaving just two to climb to the top.

This gave Sears the big floors it wanted, and by limited the floor size above, reduced the load on the elevators, and the number of elevators needed to reach the top floors. Of course, while Sears was riding high and growing like mad in 1969 when they made the original plans for the tower, but times changed. Sears never fully occupied the tower, as planned, and a much smaller Sears moved out to Hoffman Estates in 1992.

Indeed, the building has never been close to full. The original plan was for 15 75'x75' tubes, in a 5x3 configuration, with a hotel above the Sears' Merchandising Division floors. Two things stopped that. First, Sears looked at how big that building would have been, and who was paying for it. Second, the City of Chicago looked at how big that building would have been and said "Not on that plot of land." Apparently, the current owners of the building wanted, in the late 2000s, to actually build another tower over the plaza that was originally going to hold the wider building, but that didn't happen. It was actually a pretty interesting design but the economy put a stop to that.

It's not like Chicago isn't full of 2/3rds empty (or more) condo buildings as is.
posted by eriko at 4:34 AM on August 27, 2012 [5 favorites]


If you live and work at the Tme Warner Center in Columbus Circle and choose to shop at the Whole Foods there or eat at Per Se,Masa, or Bouchon Bakery every meal you never have to leave.

This is a dystopian horror story to me.
posted by Devils Rancher at 4:36 AM on August 27, 2012 [1 favorite]


Go as high as you want, you still have to come back to street level from time to time and see all those horrible poor people.
posted by orme at 5:10 AM on August 27, 2012


Except at some point you'd have to have a pretty wide spectrum of mixed-income housing and amenities. I'm picturing a scenario where at some point down the line gentrification is inevitable. All the janitors and maintenance workers end up living in the sub-baesements, meanwile the Supertower Times Style section writing smug articles about the hip clothing boutiques and artisinal pickle shops popping up on floors 35-60.

The work of J.G. Ballard suggests that this would all end very, very badly.
posted by Egg Shen at 5:41 AM on August 27, 2012 [3 favorites]


By not talking about space elevators, they miss the chance to make it about the tensile strength of materials rather than the compressive strength. Because the earth is rotating, if you put a big mass far enough out, and then tether it to the earth, the tether will be stretched as the two attempt to fly apart. (If the big mass is in geostationary orbit, it won't exert any force, compressive or tensile, on the tether, but the tether will still have to support its own weight and angular momentum).

I've read that the limits on the tensile strength of the strongest materials are more generous than the limits on the compressive strength of the strongest materials, for the same mass. People mention carbon nanotubes at this point, usually...

I've also read Larry Niven's Oath of Fealty and the better-than-I-expected "The Glass Inferno," (AKA "The Towering Inferno") and seen the not-as-good-as-I-expected "Land of the Dead," so I think there's a lot of implications of buildings as cities that this article didn't even touch on, (but the thread has.) How fortress-like they could be, and how they could be taken by siege or fire...
posted by OnceUponATime at 5:48 AM on August 27, 2012


The very idea of people having to go down to street level, to get lunch, is absurd.

But the idea of people wanting to go outside and see the sun during their work day is not. Lunch is the only convenient time.
posted by jeather at 5:50 AM on August 27, 2012 [2 favorites]


As soon as you start making mountain/volcano superscrapers, you sort of miss the whole point of skyscrapers: putting a lot of square footage on a postage-stamp. Real estate is not cheap.
posted by clvrmnky at 5:57 AM on August 27, 2012


Neglects to consider the effect that purchasing so much building material would have on the price of those materials.
posted by samofidelis at 6:03 AM on August 27, 2012


mazola: How tall can buildings get, anyway?

357,000 km. After that you have to worry about the Moon hitting it.
OK, waaaaay better than my answer!
Hicksu: 357,000 km. After that you have to worry about the Moon hitting it.

Can't you just point it the other way?
If you can assume the Moon will never change orbit versus the Earth's rotational axis, yes.
posted by IAmBroom at 6:36 AM on August 27, 2012


jake, they did! The old Maxis SimTower game was basically an elevator simulator, especially as you started to max out the available space. To some extent the successor game from the same designer was too. Fond memories...

You can get SimTower as free abandonware these days apparently.
posted by Wretch729 at 7:02 AM on August 27, 2012 [1 favorite]


Frank Lloyd Wright had plans for a mile-high skyscraper. He envisioned that a handful of such buildings would serve ALL of the office-space needs of a major city, thereby freeing up more city land for greenspace.

It is my understanding - and someone please correct this if you know more about it than I do - that one of the main reasons such a building could not be built had to do with the severe impracticality of fighting fires on its upper floors. Which seems like a very reasonable objection to me. Perhaps modern sprinker systems would be able to deal with this issue, but I'd still imagine that pressurizing water to reach the upper floors would be a difficult task, as well.
posted by Dr. Wu at 7:39 AM on August 27, 2012


At what point does the height of a tower begin to respond to the torque of the spinning of the Earth? When the top of the tower can't keep up with the base? Is that something that is already calculated into today's towers?
posted by Thorzdad at 7:55 AM on August 27, 2012


If you can assume the Moon will never change orbit versus the Earth's rotational axis, yes.

Surely the building - not to mention the civilization that constructed it - would have passed into history on the timescale involved there.

Unless you have a Space: 1999 situation, in which case all bets are off.
posted by Egg Shen at 8:17 AM on August 27, 2012


A tower built on the earth won't feel torque unless the earth's rate of spin increases or decreases. Torque, applied to something for a time, changes the rate of spin, in the same way that force, applied to something for a time, changes the velocity.
posted by sebastienbailard at 8:20 AM on August 27, 2012


Trying to make it to the Conference breakfast from the top floor of the Peachtree Tower hotel in Atlanta, I called the desk about the elevator delay, and they told me that at peak times it could take up to fifteen minutes for an elevator to get up there. There were only two or four elevators, and no express, as I recall.

That's why there are mirrors outside elevators.
posted by StickyCarpet at 8:30 AM on August 27, 2012


Yeah, some relevant SF texts here are:

* Niven & Pournelle's Oath of Fealty - Semi-fascist arcology beats lame democratic city because, libertarianism)
* Ballard's High Rise - Modern apartment living makes people really, really unpleasant. Like Lord of the Flies levels unpleasant.
* Marusek's Getting To Know You - Yep, poor people get stuck down in the sub-basements of these mile high apartment complexes. Not that nice down there.
* Chiang's Tower of Babylon - The limit to a building's height is the vault of Heaven.
posted by Chrysostom at 8:32 AM on August 27, 2012 [4 favorites]


At what point does displacing all that mass upwards slow the earth's rotation down though? Build enough of these things, and our days will get measurably longer.

Build enough of them on the same side of the Earth, and it'll start to wobble.
posted by Devils Rancher at 8:33 AM on August 27, 2012


You're fundamentally misunderstanding the scale of these towers with respect to the scale of the Earth. Not only is a mile-high tower barely a tiny bump compared to the diameter of the planet, but the mass displaced upward (outward) is insignificant compared to Earth's mass.

I'd imagine water evaporated into the air by global warming would have a much bigger effect, and that's still probably negligible, since we haven't heard anything about longer days due to global warming.
posted by explosion at 8:52 AM on August 27, 2012


The very idea of people having to go down to street level, to get lunch, is absurd.
Which is why there is a food truck with a roof-mounted trebuchet in your future.

One issue that didn't come up was plumbing. Poop at terminal velocity is no joke.
(Ok, I lie. Poop at terminal velocity is like the perfect potting soil for joke germination.)
posted by Killick at 9:19 AM on August 27, 2012 [1 favorite]


I was just musing. I wonder how tall and massive a structure would have to be in order to slow our rotation by, say, 1/100th of a second? 1/4 mile wide & 25,000 ft. tall? Surely, if we leveled everest & duped all the rock into the Marianas trench, we'd speed up by a measurable amount. & by measurable, I mean with delicate instruments, of course.
posted by Devils Rancher at 9:33 AM on August 27, 2012


Ever since I saw The Towering Inferno, I have sworn that I will never happily live or work in a building that was too tall for me to take the stairs out in case of a fire.

Since then, faulty elevators and blackouts have convinced me that I really don't want to live or work in a building too tall for me to take the stairs UP to where I need to be. As curiosities, super-tall buildings are amusing, but they are so impractical in reality. Extremely high-density can be achieved with medium-rise and high-but-not-stupidly-high-rise development, at a much lower cost and with so many fewer problems.

Indeed, I've heard that for residential, dense low-rise can be as dense or denser than a lot of medium and high-rise residential - and people seem to far prefer it.
posted by jb at 9:43 AM on August 27, 2012


Killick: "One issue that didn't come up was plumbing. Poop at terminal velocity is no joke."

Getting poop out is pretty well figured out. Getting water up will be more challenging.
posted by Chrysostom at 11:06 AM on August 27, 2012


That's just fascinating. Skyscraper plumbing is a subject I've never considered, but upon reflection it sounds like a miracle of modern engineering.
posted by Kevin Street at 12:26 PM on August 27, 2012


An interesting implication of the megabuilding is that at some point it becomes cheaper for them to be self-sufficient in terms of power and food by using local renewables and by having embedded agriculture and maybe aquaculture for fish.
posted by feloniousmonk at 1:29 PM on August 27, 2012


* Niven & Pournelle's Oath of Fealty - Semi-fascist arcology beats lame democratic city because, libertarianism)

Wow, way to bring out your pre existing narrative on this one. The book is really about a different way to do a city and how the new society within that city will not be loyal to the society outside the city. The government structure within the arcology is more closely akin to feudalism, as the title alludes too. They do make some references to free market capitalism and the invisible hand of the market (in the adam smith sense, not the modern libertarian meaning).

These two authors are definitely conservative, but they are NOT libertarian in any sense. They both believe and espouse for a strong, if limited, central government and both are very big believers in a federal system of powers, with as much power as possible pushed down to the local level.

And the book is good, but the building is mostly just big, not all that tall, with the important part of it being totally self contained. And they do really gloss over the lives of the lower castes in the building and where/how they live.
posted by bartonlong at 1:55 PM on August 27, 2012


Here's a good breakdown of how the Sears (Willis) Tower tube structure works.

eriko's explanation is good but I'm a visual-type person and this helped.
posted by deborah at 2:13 PM on August 27, 2012 [1 favorite]


eriko: "It was actually a pretty interesting design but the economy put a stop to that."

Eriko, that site is fascinating, albeit time-sucking, thank you!
posted by Sportbilly at 2:51 PM on August 27, 2012


bartonlong: "the building is mostly just big, not all that tall, with the important part of it being totally self contained. "

True, I think Todos Santos was 1000' feet tall, so maybe 75-80 stories? Someone had mentioned arcologies earlier, which is why I'd brought it up.
posted by Chrysostom at 6:23 PM on August 27, 2012


Malor writes "Yeah, as Chef Flamboyardee is saying, I believe atmospheric pressure is the real limit. Per Wikipedia, the Boeing 767 pressurizes the passenger cabin to the equivalent of 6900 feet, 2100 meters, while the A380 pressurizes to 5000 feet, 1,500 meters. "

And Mexico City is at 7900 feet.

Chrysostom writes "Getting water up will be more challenging."

This is a trivial problem of engineering.
posted by Mitheral at 8:03 PM on August 27, 2012


Other SF treatments that come to mind: Peaches for Mad Molly by Steven Gould; Farewell Horizontal by Jeter; and if you're willing to stretch a little there's always Trantor and its many imitators.

Forget the 40 lanes of road-- it would need 25 million square feet of parking structures

Upon reflection, although the vertical subway/lightrail scheme should work fine, the proper solution is probably just to have a ring of Zeppelin docks every 150 floors or so.

at a much lower cost and with so many fewer problems

Lower cost? Fewer problems‽ *splutter* Sir, this is the future of architecture we're talking about, not some, some timid child's treehouse! *puts on tophat, goes back to drawingboard to sulk, stare at bust of I K Brunel, play with Solieri action figure* Fewer problems, indeed! As if anyone wants fewer problems!
posted by hattifattener at 8:06 PM on August 27, 2012


This is a trivial problem of engineering.

I would assume that you could just pump the water up to some level, let it accumulate in a big bucket or something that opens to the air and equalizes the pressure...then interate pumping from that reservoir right? You don't need to have the water flowing in one giant continuous pipe the whole way...

But all my plumbing experience is for UHV equipment...so I'm just spittballing here.
posted by Chekhovian at 8:08 PM on August 27, 2012


I would assume that you could just pump the water up to some level, let it accumulate in a big bucket or something that opens to the air and equalizes the pressure...then interate pumping from that reservoir right? You don't need to have the water flowing in one giant continuous pipe the whole way...

This does work, and is the old school way of doing it. With modern variable speed pumps you just put booster pumps every so often and they only work as hard as they need to to supply the desired volume. Virtually all muncipal systems work on this style pump now and it is how they solve the elevation problem without too much pressure in hilly towns like san francisco or Flagstaff or lots and lots of others.
posted by bartonlong at 8:16 PM on August 27, 2012


So the modern solution is just use stronger pumps? Typical...I think in the giant building case, the question is when the pressure at the base of the pipe is bigger than the bursting pressure of your available pipes...

Actually...you might be able to use some tricks from the oil industry, after all they work real hard on pumping stuff over big height differentials...you could introduce air bubbles into the pipe that would rise up with pockets of water in between them...that would fix you big pressure head problem.
posted by Chekhovian at 8:50 PM on August 27, 2012


A lot of these ideas ignore a couple of interesting interrelated questions: how long is it going to last? what problem does it solve?

The pyramids (all over) got the first part right, but the second part did most of them in. Rationally, these enormous investments of materials and human lifetimes (in the face of human deprivation) can only be viewed as ego-driven stunts unless they deliver value that exceeds the investment. Clearly Eiffel, Giza and NASA have delivered entertainment value. NASA has delivered more (if it can be retained): knowledge. OTOH, like most of the world's pyramids, Burj Khalifa became a tragedy when the first shovel turned.
posted by Twang at 9:11 PM on August 27, 2012


So the modern solution is just use stronger pumps?

No, the modern solution bartonlong describes is a lot like the "intermediate reservoirs" system you described except without the intermediate reservoirs. You have pumps spaced out vertically and the pumps are designed to be able to work in series like that under variable demand.

Deep water wells sometimes use multiple pumps as well, probably more of a bang-bang control though.
posted by hattifattener at 9:52 PM on August 27, 2012


At what point does the height of these theoretical buildings (being, I assume, in populated areas near transportation nodes) become a nuisance/obstacle/danger for aircraft flightpaths?
posted by psoas at 6:20 AM on August 28, 2012


hattifattener: "Other SF treatments that come to mind: Peaches for Mad Molly by Steven Gould; Farewell Horizontal by Jeter; and if you're willing to stretch a little there's always Trantor and its many imitators.
"

Trantor has a really unrealistically low population density.

I can't remember if Donald Kingsbury fixed this in his Foundation-with-the-serial-numbers-filed-off Psychohistorical Crisis.
posted by Chrysostom at 7:02 AM on August 28, 2012


As stated booster pumps will allow for you to lift the water as high as you want without storage tanks. However most buildings are going to include storage tanks anyways as a hedge against fire, blackouts or lack mains water pressure.

Also you might want the water on hand for cooling. Some of the buildings in Toronto get water from the cold depths of the nearby lake. This water is then used for cooling which a) saves money on AC and b) saves money on heating the water for hot water use.
posted by Mitheral at 12:26 PM on August 28, 2012


I was just musing. I wonder how tall and massive a structure would have to be in order to slow our rotation by, say, 1/100th of a second? 1/4 mile wide & 25,000 ft. tall? Surely, if we leveled everest & duped all the rock into the Marianas trench, we'd speed up by a measurable amount. & by measurable, I mean with delicate instruments, of course.

Because of differences in latitude, the top of Everest is something like 585km closer to Earth's rotational axis than the bottom of the Mariana Trench. So to detect an increase in Earth's speed, we'd need to use instruments that are not merely delicate, but in fact, broken.

I did some math which probably is wrong, and came up with the result that doing this would extend the days by 102 microseconds. For comparison, that's roughly equal to 6 years worth of earth's natural slowing down due to tidal acceleration.

This of course is all idealized. In reality, this effect would be less pronounced, because when you lifted Mt. Everest, the crust there would spring back out a bit, and the reverse would happen wherever you put it back down.
posted by aubilenon at 2:52 AM on August 29, 2012


boo, i was going to say space elevators :P
posted by TrinsicWS at 3:14 AM on August 29, 2012


I'm now imagining elevators that can "change lanes" so to speak, so they can switch to between the up and down shafts, and passing shaft and the slow shaft.

By the elevator doors, it will have little maps with coloured lines letting you know which elevators stop at which combination of floors. There will be 100, 50, 20, 2 and 1 elevators, which all stop at floors that are multiples of their corresponding numbers, also if you are descending to anything below the 70th floor, you will need to note which of the four legs of the building your elevator will take to the ground.

You also got me checking my copy of Kate Ascher's The Works, to see if it addresses elevators. It does not appear to, though it does briefly touch on the issue of pumping water up taller buildings.
posted by RobotHero at 10:47 PM on August 29, 2012


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